Association between body fat distribution and androgen deficiency in middle-aged and elderly men in China

Association between weight-adjusted waist index and testosterone deficiency in adult American men: findings from the national health and nutrition examination survey 2013-2016

BACKGROUND

Testosterone deficiency (TD) and obesity are globally recognized health concerns, with a bidirectional causal relationship between them. And a newly discovered obesity indicator, the Weight-Adjusted-Waist Index (WWI), has been proposed, demonstrating superior adiposity identification capability compared to traditional body mass index (BMI) and waist circumference (WC) indicators. Therefore, we present the inaugural investigation into the associations of WWI with total testosterone levels and the risk of TD.

METHODS

Data restricted to the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2016 were analyzed. Only males aged > 20 years who completed body measures and underwent serum sex hormone testing were potentially eligible for analysis. Weighted multivariable linear regression and logistic regression analyses were employed to investigate the relationships between WWI and total testosterone levels, and the risk of TD, respectively. Smooth curve fittings and weighted generalized additive model (GAM) regression were conducted to examine the linear relationship among them. Additionally, subgroup analyses with interaction tests were performed to assess the stability of the results.

RESULTS

Finally, a total of 4099 participants with complete data on testosterone and WWI were included in the formal analysis. The mean age of study participants was 46.74 ± 0.35 years with a TD prevalence of 25.54%. After adjusting all potential confounders, the continuous WWI displayed a negative linear relationship with total testosterone levels (β=-61.41, 95%CI: -72.53, -50.29, P < 0.0001) and a positive linear relationship with risk of TD (OR = 1.88, 95%CI: 1.47, 2.39, P < 0.0001). When WWI was transformed into quartiles as a categorical variable, participants in Q4 exhibited lower total testosterone levels (β=-115.4, 95%CI: -142.34, -88.45, P < 0.0001) and a higher risk of TD (OR = 3.38, 95% CI: 2.10, 5.44, P < 0.001). These associations remained stable in subgroup analyses without significant interaction (all P for interaction > 0.05).

CONCLUSIONS

This investigation firstly unveiled a negative linear association between WWI and total testosterone levels, coupled with a positive linear relationship with the prevalence of TD in U.S. male adults aged 20 years and older. Further studies are needed to validate the potential utility of WWI for the early identification and timely intervention of TD.

Cardiorespiratory fitness and the relationship between body fat and resting testosterone in men

Objective: To examine the effect of cardiovascular fitness, i.e. VO₂max, on the relationship between weight status and resting testosterone level (RTL) in males.Materials and methods: A subset of male participants from the 2003-2004 National Health and Nutrition Examination Survey were analyzed by weight status, i.e. normal, overweight, obese, and all participants. Bivariate correlation coefficients were computed for RTL, percent body fat (BF%), and VO₂max. Partial correlation coefficients were computed between RTL and BF% controlling for VO₂max and between RTL and VO₂max controlling for BF%.Results: Bivariate correlations between RTL and BF%, and RTL and VO₂max were significant in all groups. The partial correlation coefficients between RTL and BF% controlling for VO₂max were significant in the normal and all participants group. When RTL and VO₂max were analyzed controlling for BF% only the all participants group remained significant.Conclusion: Cardiovascular fitness or weight status may independently influence RTL in males.

Comparison of Anthropometric Measures for Evaluating the Association Between Hypogonadism and Hypothalamic-Pituitary-Gonadal Hormones in a Taiwanese Population

To investigate the degree of association between levels of sex hormones and anthropometric indices in male population. A cross-sectional survey was conducted between July 2014 and July, 2016, in a men's health polyclinic in Taiwan. Body mass index, waist circumference, waist-to-height ratio (WHtR), and conicity index were tested. Serum total testosterone, free testosterone, and dehydroepiandrosterone sulfate (DHEA-S) were measured. Decreased testosterone levels were correlated with the four indices (r = -0.09 to -0.27, p < 0.01). In hypogonadism group, DHEA-S deficiency was associated with older age, higher anthropometric indices, and chronic illness. The areas under the receiver operating characteristic curves of hypogonadism and DHEA-S deficiency by the four anthropometric indices ranged from 52.5% to 65.9%. Logistic regression analysis revealed that obesity, defined by the four indices, was associated with increased risk of hypogonadism. Moreover, obesity was also associated with increased risk and DHEA-S deficiency. Anthropometric indices analyzed are associated with lower testosterone and DEAH-S deficiency. A WHtR of 0.5 is suggested to be a simple and reliable indicator of hypogonadism and DHEA-S deficiency.